Honours Project Opportunities Plant Developmental Genetics
The research in my lab is centred on understanding mechanisms regulating plant shoot development, in particular how shoot meristems are maintained and how leaf organs are patterned and how these processes interconnect with plant growth. We work with the model dicot plant Arabidopsis thaliana and the model grass Brachypodium distachyon. Further information can be found at http://sydney.edu.au/science/biology/about_us/academic_staff/byrne_mary/.
Plant development; plant shoot architecture; meristem function; leaf polarity; regulation of gene expression; ribosome function
Potential Honours Projects
Supervisor: Mary Byrne
Plant shoots are characterized by the presence of a shoot apical meristem, which is established in the embryo and maintained throughout growth of the plant. The shoot meristem iteratively produces lateral organs and ultimately gives rise to all organs of the plant shoot. The meristem also influences the final shape or pattern of a leaf. Control of meristem function and leaf patterning occurs via a network of gene interactions and involves transcriptional and post-transcriptional mechanisms. We have identified ribosomal proteins as part of this network. Mutations in ribosomal protein genes have a range phenotypes, however, there are specific defects in meristem function and leaf patterning in the embryo and in the shoot. Ribosomal protein mutants also reduce fertility through effects on female development. We are currently investigating how ribosomal proteins affect development and we are exploring the mechanism of ribosome-mediated regulation of development. An honours project will aim to determine the contribution of different ribosomal proteins to embryo development by comparative analysis of ribosomal protein mutants. This work will contribute to an understanding of the roles of ribosomal proteins during development.
Supervisor: Mary Byrne
Cereal grasses are a major source of human nutrition, providing approximately 40% of world dietary energy needs. Additionally, grasses have multiple non-food crop uses, and have significant potential as sources of renewable energy, with biomass representing a key trait that impacts on utility for energy production. Brachypodium distachyon is currently being developed as a model for molecular genetic studies of grasses, particularly as it is closely related to wheat and other major food and forage crops. Unlike these crop species, Brachypodium is fast growing and has a small genome that has recently been sequenced. The Brachypodium sequence provides an invaluable resource to identify genes involved in grass development. As an approach to understanding genetic regulation of shoot development in grasses we have established a mutant resource of Brachypodium and identified mutants disrupted in inflorescence development. An honours research project will involve characterization of the phenotype of one of these mutants using various microscopy techniques and will analyze the expression levels of key developmental genes in the mutant to compare with wild type. The project will provide important information on our understanding of grass reproductive development.
Supervisors: Mary Byrne and Simon Ho
In Eukaryotes, the cytoplasmic 80S ribosome is a multimeric complex comprising a large and a small subunit with around 80 distinct ribosomal proteins contributing to these two subunits. All ribosomal proteins in Arabidopsis are encoded by small gene families, of two to five genes. One possible explanation for the presence of multiple genes for each ribosomal protein is retention of these genes following genome duplication in order to maintain stoichiometric ratios of the ribosomal proteins that make up the multi-protein complex of the ribosome. The available Arabidopsis thaliana genome sequence and recent release of the genome sequence of the closely related species Arabidopsis lyrata, allows testing of this idea. In this Honours project the student will carry out comparative sequence analysis and determine rates of sequence divergence for ribosomal protein genes in two closely related Arabidopsis species. The results of this project will have broader significance in understanding why certain types of closely related genes are present in multiple copies in genomes.